A Nickel-Based Coordination Compound with Tunable Morphology for High-Performance Anode and the Lithium Storage Mechanism

Metal-organic coordination compounds (MCCs) have received a lot of attention as anodes for lithium-ion batteries (LIBs) due to their abundant structural configuration, tunable morphology, high surface area, and low cost, but the lithium storage mechanism of MCCs is still a mystery. Herein, we synthesized a kind of nickel-based coordination compound (marked as Ni-PP-x, x = 1, 2, or 3) with tunable morphologies and different solvent ratios via a microwave irradiation solvothermal method and then applied them as anodes for LIBs. Among them, the Ni-PP-2 electrode, with a hollow and urchin-like structure, showed the longest lifespan and maintained a high capacity of 713 mAh g(-1) at 2.0 A g(-1) after 800 cycles. Measured by ex situ X-ray photoelectron spectroscopy (XPS) and ex situ Fourier transform infrared spectroscopy (FT-IR), the Ni-PP-2 electrode was confirmed by a redox reaction mechanism of Li+ cations with a benzene ring and O-Ni2+/O-Ni-0 coordination bonds, and the cyclic voltammetry curves have exhibited a capacitive dominated lithium storage behavior. This work provides a new type of Ni-based coordination compound and an in-depth understanding of their lithium storage mechanism, paving the way for the application of MCC compounds in the future.

Automated summary

In this study, a nickel-based coordination compound Ni-PP-x was synthesized and applied as an anode for lithium-ion batteries. The Ni-PP-2 electrode with a hollow and urchin-like structure exhibited a long lifespan and high capacity. An in-depth understanding of the lithium storage mechanism was achieved through the investigation of redox reaction mechanism and cyclic voltammetry curves. This work provides new insights for the future application of metal-organic coordination compounds in lithium-ion batteries.